{"uid":"cap_vn13SBwLYYSeo3Tvpb1TE","slug":"fetchdelta-com-4ba3edb5","name":"FetchDelta Diff API","description":"Compare a public page against its previous snapshot and return structured changes plus a 30-day daily-watch upgrade.","url":"https://fetchdelta.com/api/diff","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["url"],"properties":{"url":{"type":"string","format":"uri","description":"Absolute URL of a public HTTP(S) page to fetch. Use docs, changelogs, release notes, pricing pages, policy pages, or other public pages. Private, localhost, credentialed, and non-HTTP(S) URLs are rejected."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"url":"https://example.com/","preview":[{"text":"New paragraph","type":"added"}],"addedLines":3,"hasChanges":true,"removedLines":1,"baselineCreated":false,"monitoringUpgrade":{"price":"$0.50","method":"GET","maxUrls":5,"product":"page-watch-30d","currency":"USDC","protocol":"x402","checkoutUrl":"https://fetchdelta.com/api/page-watch-30d?url=https%3A%2F%2Fexample.com%2F","description":"Create an account-free daily change watch for this page, valid for 30 days.","durationDays":30}}},"example":{"request":{"input":{"type":"http","method":"GET","queryParams":{"url":"https://example.com"}}},"response":{"url":"https://example.com/","title":"Example Domain","excerpt":null,"preview":[{"text":"Example Domain\n\n# Example Domain","type":"added"}],"finalUrl":"https://example.com/","addedLines":4,"hasChanges":true,"currentHash":"7ed444d98c01f117436841a0d196e05b616481c96dc699d5d50f3360bcbb32e9","removedLines":0,"baselineCreated":false,"currentFetchedAt":"2026-05-29T18:54:16.992Z","previousFetchedAt":"2026-03-31T11:00:55.711Z"}},"exampleRequest":{"url":"https://example.com"},"tags":["x402"],"displayCostAmount":"0.004","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.004/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_UOXEC1o1VXt7fzisFx0FC","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.004","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Compares the latest fetched content of a web page with its previous snapshot and returns structured changes (diffs).","exampleAgentPrompt":"Can you check what has changed on https://example.com/pricing since the last time it was fetched and show me the structured diff of any content updates?","exampleUseCases":[{"title":"Monitor competitor pricing page updates","prompt":"Keep an eye on https://competitor.com/pricing for me — if anything has changed since the last snapshot, show me exactly what was added or removed so I can see if they've adjusted their plans or prices."},{"title":"Track open source changelog for new releases","prompt":"Can you check https://github.com/some-project/blob/main/CHANGELOG.md and tell me what's new since the last time it was fetched? I want to know if there are any new releases or breaking changes I should be aware of."},{"title":"Alert on terms of service modifications","prompt":"Pull up https://someservice.com/terms and compare it to the previous snapshot — have they changed anything in their terms of service recently? Highlight any sections that were added, removed, or reworded."}],"resultDescription":"A structured object describing the differences between the current page content and the previously stored snapshot — including added, removed, or modified sections of the page.","failureModes":["URL is unreachable or returns a non-200 status — diff cannot be computed","No previous snapshot exists for the URL — first-time fetch with nothing to compare against","URL parameter missing or malformed — validation error returned","Page content is unchanged — empty or null diff returned","Rate limit or payment failure — 402 or 429 error"],"whenToPreferThis":"Use this endpoint when you need to detect what has changed on a specific web page between the current fetch and a prior snapshot. It is the right choice for monitoring pages for updates, verifying content changes, or alerting on modifications — especially when you already have a prior crawl stored and want a structured diff rather than raw content.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:33:03.409Z","isFirstParty":false}